Auth bypass in MongoDB Server

CVE-2026-120816

A user with basic read-tier database privileges can use an option on a server-side data-change notification feature to receive the contents of certain restricted internal collections that the same user is refused on a direct read. The privilege check for the notification feature is derived only from the target namespace and does not account for the option, so no additional permission is required. This may result in unintended access to data stored in those internal collections.

Vulnerability class: Broken Access Control

Published · last modified .

CVSS v3 metric

CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-120816?
CVE-2026-120816 is a medium-severity vulnerability in MongoDB Server, classified under Incorrect Authorization. CVSS score: 4.3/10. Published 2026-11-10.
How severe is CVE-2026-120816?
Medium severity. CVSS v3 base score is 4.3 out of 10.